Building with aluminum door and window frames had been common for many years. Traditionally, the masons build a wall of cement blocks, with cement pillars and beams, leaving openings to receive the windows and doors. These openings are of approximately the size and in approximately the location of the doors and windows in the architect's plans, although precision is difficult if not impossible.
The aluminum specialist then measures the openings in the walls, and makes a custom blind frame of the correct dimensions for each opening. The blind frame is hidden in wall, and an outer frame holding a window sash or door panel is mounted thereon. The blind frame is disposed in the opening and affixed in place by means of bolts extending through the frame and into the cement defining the opening. It will be appreciated that this structure is not particularly stable, and cracks often appear in the plaster around the door and window frames, over time.
The window or door outer frame is then mounted on the blind frame and sealed in place with silicone to provide the desired seal to prevent moisture and wetness. Similarly, the jambs holding the door or window pane are mounted on the outer frame and sealed with silicone. It will be appreciated by those skilled in the art that the use of silicone is expensive and does not provide a flexible seal over time. Rather, inexpert work in inserting the silicone in place can cause water leakage. On the other hand, removing dried silicone is extremely inconvenient.
This building method is very labor intensive, as each window must be custom made for its frame, which is manufactured for it, and cannot be mounted in another opening. Furthermore, the frames are not sturdily mounted in the walls, leading to cracking of plaster around the frames, and often to loosening of the frame, which can result in the reduction of insulation of the room or building.
Accordingly, there is a long felt need for, and it would be very desirable to have a blind frame which is stable once in place, and it would be desirable to have such a frame which is substantially modular or of standard sizes.
The building methods described above relate to conventional building methods. However, it will be appreciated that many buildings are now prefabricated and assembled by industrial methods, such as using pre-cast elements which can be rapidly mounted on site. In such buildings, a portion of a wall is formed, a mold is built on the outside surface, an outer frame for each window is mounted in the wall, a mold is built on the inside surface, and concrete is cast into the mold. When the window has decorative elements, for example on the wall around an interior or exterior frame, these elements must be added later with the plaster, exterior cladding and other finish.